Isolated cardiac sarcoidosis: establishing the diagnosis with electroanatomic mapping-guided endomyocardial biopsy.

Diagnosing isolated cardiac sarcoidosis can be challenging, and requires a high index of suspicion. We report a case of a young woman who presented with sustained ventricular tachycardia, intermittent atrioventricular block and epsilon wave on electrocardiogram. Although the patient fulfilled Task Force criteria for arrhythmogenic right ventricular cardiomyopathy, sarcoidosis was suspected because of the presence of intermittent atrioventricular block. As illustrated in this report, the use of electroanatomic mapping-guided endomyocardial biopsy can be decisive in achieving the diagnosis and is a valuable approach in cases of suspected isolated cardiac sarcoidosis.